#include <bits/stdc++.h>

using std::list;

#define Nadejde 100000

int N, M;
list <int> adj[Nadejde + 1];
char seen[Nadejde + 1];

/** Exploreaza recursiv graful. **/
void dfs(int u) {
  if (!seen[u]) {
    seen[u] = 1;
    for (list <int>::iterator it = adj[u].begin(); it != adj[u].end(); it++) {
      dfs(*it);
    }
  }
}

int main(void) {
  int i, u, v;
  FILE *f = fopen("dfs.in", "r");

  /* Citirea datelor. */
  fscanf(f, "%d %d", &N, &M);
  for (i = 1; i <= M; i++) {
    fscanf(f, "%d %d", &u, &v);
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  fclose(f);

  /* Calcularea solutiei. */
  int numSeen = 0;
  for (u = 1; u <= N; u++) {
    if (!seen[u]) {
      dfs(u);
      numSeen++;
    }
  }

  /* Afisarea solutiei. */
  freopen("dfs.out", "w", stdout);
  fprintf(stdout, "%d\n", numSeen);
  fclose(stdout);

  /// Multumim Doamne!
  puts("Doamne ajuta!");
  return 0;
}